Elevator belt driving mechanism



April 1o, 1934;

A. E. ROTHGARN 1,954,493 ELEVATOR BELT DRIVING MECHANISM Filed Deo. l, 1930 l2 Sheets-Sheet l April l0, 1934. A. E. ROTHGARN ELEVATOR BELT DRIVING MECHANISM 2 Sheets-Sheet 2 Filed Dec. l, 1930 Patented Apr. 10, 1934 r,UNITED STATES ELEVATOR BELT DRIVING MECHANISMIV Andrew E. Rothgarn,

Minneapolis, Minn., as-

signor to Samuel C. Clow, Minneapolis, Minn. Application December 1, 1930, Serial No. 499,199

2 Claims.

This invention relates to elevators of the type wherein bucket-equipped. belts are run over upper and lower pulleys 'and through a boot and ele- Vator legs and wherein the power for driving the elevator is applied or attached to the elevator head; and generally stated, the invention consists of the novel devices, combinations of devices and arrangement of parts hereinafter described and defined in the claims.

Elevators of the above type are especially desirable for the elevation or" grain in grain elevators and where grain is to be stored or handled. In the use of the bucket-equipped elevator belts, v the buckets on the rising side of the belt will, of course, be filled with grain while those on the opposite side will return empty. This throws such an excessive amount of weight on the loaded side of the belt that, in the absence of means for preventing backward movement of the loaded side of the elevator belt, .the belt 'will run backward and downward whenever the driving power is disconnected from the belt-guiding or carrying pulleys or wheels. Worm and gear drives have hitherto been used for the above purpose on the assumption that such worm and gear drive will lock the loaded side of the belts against backward movement.

My invention provides a two-step speed reduction transmission of very simple construction, be-

- tween an electric motor and the elevator beltdriving pulley, which operates under a minimum of friction and in itself is or would be reversible but as an important feature, I provide an automatic back lock or device that will prevent backward or downward movement of the loaded side of the belt in case the driving power is disconnected from the belt-driving pulley or when inactive thereon. A v

A commercial form of the invention is illustrated in the accompanying drawings, wherein like characters indicate like parts throughout the several views.

4,Referring to the drawings:

Fig. 1 is a View in side elevation showing the head and upper portions of the elevator and illustrating the application of my invention thereto;

Fig. 2 is a plan View of the parts shown in Fig. 1, some parts being broken away and some parts being sectioned;

Fig. 3 is asection on the line 3--3 oi Fig. 2;

Fig. 4 is a section on theline 4-4 of Fig. 2;

Fig. 5 is a transverse section taken on the line 5--5 of Fig. .1; and

Fig. 6 is a vertical section taken on the line 6-6 of Fig. 2. Y

Of the parts of the elevator proper, the numeral 7 indicates the elevator legs that lead upward from a lower hopper, not shown, and are connected to an elevator head 8, which, as shown, is provided with a discharge spout 8b. The

bucket-equipped belt 9 runs over an upper driving wheel in the form of a pulley 10. This pulley 10 is carried by a shaft 11 journaled at one end in a bearing l2 on one of the beams 8a of the head 8. Pulley shaft 11, at its other end is extended and is journaled in a sleeve 13 of a gear casing 14, the said journal as shown being afforded by roller bearings 15. Gear casing 14 is rigidly secured to the elevator head, as shown, being provided with projecting brackets 16 secured to the adjacent beam 8a by screws or bolts 17. A motor-supporting table 18 is also bolted to the adjacent head beam 8a at 19 and to one side of the gear casing 14 at 20. A large spur gear 21 is located within the gear casing 14, is keyed or otherwise rigidly secured to a projecting end of pulley shaft 11, located within the gear casing 14 and meshing with spur gear 21 is a relatively small spur pinion 22 that is keyed or otherwise rigidly secured to a short countershaft 23 journaled in the gear casing in a manner presently to be described. A bevel gear 24, preferably of the spiral bevel gear type, is also keyed or otherwise rigidly secured to countershaft 23 adjacent the pinion 22.

A complete gear case 14 is provided with a detachable outer side plate 25 that is rigidly but detachably secured thereto by machine screws 26 or the like. The back of the gear casing 14 and the removable side plate 25 are formed with short outstanding aligned sleeves 27 in which are located ball bearings 28 that are capable of lateral shifting movements within the said sleeves. The ends of the countershait 23 are secured in the inner members of said ball bearings. Aligning heads 29 work in the sleeves 27, against the outer members of the ball bearings 28, and are provided with threaded axial stems 30 that project through sleeve heads 3l that are rigidly but detachably secured to the respective sleeves 27 by'machine screws 32 or the like.

At their outer ends, stems 30 are shown as provided with lock nuts 33 for holding the same in various lateral adjustments. The numeral 34 indicates small set screws that work through the hubs of the heads 31 and engage the threaded sleeves 30 to lock the same in set adjustments.

Spiral bevel gear 24 is engaged by a relatively small spiral bevel pinion 35 secured on the end of a secondary driving shaft 36 which, by suitable ball bearings 37, is journaled in a sleeve-like projection 38 of the gear casing 14. Here it will be noted that the gear casing 14 is provided with a second sleeve-like projection 33a that is a duplicate of sleeve 38 and is axially aligned therewith so that the ball bearings 37 and hence the shaft 36 may be mounted at either side of the gear case and spur gear. At this point it may be also noted that the gear casing 14, diametrically opposite its connection 20 has the table 18 with a flattened surface 20a so that said table may be attached to the gear case on either side of the spur gear 2l. This, as will presently be noted, makes it possible to couple up the electric driving motor at either side of the gear casing. For closing the sleeve 38 when not used as a bearing, there is shown a small head 39. To the projecting end of the sleeve 38 there is detachably but rigidly secured a peripheral notched ratchet-acting lock wheel 40, the iianged hub of which fits against the end of said sleeve 33 and is secured thereto by machine screws 41 or the like. The wheel 40 is therefore, of course, fixed or nonrotary. Keyed or otherwise secured to the projecting end of shaft 36 is a wheel lock head or disc 42 that serves as a lock dog carrier and to which, as shown, a plurality of small lock dogs or pawls 43 are pivoted in position to engage the teeth or notches of lock wheel 40. The numeral 44 indicates small holes in the head 42 through which nails or the like may be passed to hold the dogs 43 outward in inoperative positions when desired. The head 42 is provided with a drumlke peripheral flange 45 that is adapted to be engaged and used as a brake drum under conditions and in a manner presently to be noted.

The casing 46 of an electric motor is rigidly anchored on the table 13 and the shaft 47 of its rotor is approximately axially aligned with the shaft 36 and at its projecting end, it carries a disc-like head 48 that is spaced from the head 42. The heads 42 and 48 are provided, respectively, with projecting coupling' pins 49 and 50. As shown, each of said heads has four of such pins in parallel relation, with the pins 49 and 50 alternated circumferentially. A quite stiff but somewhat nexible endless coupling belt 51 of heavy leather or the like is passed over the pins 50 and under the pins 49. The coupling made up of the elements just described has a very considerable iiexibility which makes exact alignment of the shafts 46 and 47 unnecessary and, moreover, gives some flexibility to the coupling in the starting and stopping of the driving mechanism.

In the operation of the driving mechanism described, the rst step of reduction in the motor speed takes place between the bevel pinion 35 and bevel gear 24 and the second step in the reduction takes place between the spur pinion 22 and spur gear 21. All of this driving mechanism including the motor is mounted as a self-contained unit on the head of the elevator structure where their adjustments are not affected or changed by a settling of the building in respect to the foundation of the elevator leg or conversely. By lateral adjustments of the heads 29, the ball bearings 28 and hence countershaft 23, together with pinion 22 and bevel gear 24 may be given slight adjustments toward the front or toward the back of the gear casing so as to set the bevel gear 24 in exact and proper intermeshing contact with bevel pinion 35.

When the motor is in action, driving shafts 36 and 47 and head 42 will be rotated in a counterclockwise direction in respect to Fig. 3 and under such direction of rotation, dogs 43 will slip over the teeth of the back rotation lock wheel 40 and when normal driving speed has been acquired, said dogs will be thrown out of clicking Contact with the teeth of said wheel 40. As soon, however, as the driving mechanism is stopped or even nearly stopped, some of the dogs 43 will engage the teeth of the wheel 40 and thereby positively lock driving mechanism against backward movement andthe loaded side of the elevator belt 9 against downward movement. If at any time it should be desirable to allow the loaded side of the belt to move downward, then dogs 43 can be secured in retracted positions indicated by dotted lines in Fig. 3 by inserting nails or the like in the small holes 44; and at such time to prevent too rapid downward movement of the loaded side of said belt, a small wooden bar or the like placed against the edge of the table 18 and pressed against the drum surface 45 of head 42 can operate as a brake device for retarding 'such movement or, if desired, for rstopping the same at any particular point.

It will, of course, be understood that various changes in the details of construction and arrangement cf parts may be made without departing from the spirit of the invention herein disclosed and claimed. For instance, the elevator belt driving wheels instead of being pulleys might be sprocket wheels.

When the side plate 25 of the gear casing is removed, access is afforded to 'all of the gears so that they may be applied or removed from the gear casing proper. It is important also to note that the dog-equipped head 42 of the back motion lock or stop device is carried by 'the high speed motor-driven shaft or member 3G and hence is rendered not only sensitive to centrifugal force to throw the dogs out of action when rotated in the driving direction, but in which application a comparatively small lock device will suffice, whereas a much longer and much larger and stronger device would lbe required if applied to a slower running member of the transmission mechanism.

The square or rectangular teeth on ratchet wheel 40 adapts the same to cooperate with pivoted dogs regardless of the direction in which the said dogs are extended circumferentially of said wheel.

What I claim is:

1. The combination with a conveyor and a motor, of speed reducing connections between said motor and conveyor including a rotary wheel, an anchored non-rotary notched stop wheel located concentric to and closely associated with said rotary wheel, said rotary wheel having a plurality of circumferentially spaced freely pivoted gravity and centrifugally actuated dogs, certain of which will be always engaged with said notched stop wheel when said rotary wheel is at rest or at slow speed, but all of vwhich will be centrifugally thrown out of action when said rotary wheel has acquired a predetermined speed, whereby backward rotation of said rotary wheel will be prevented, said anchored stop wheel having approximately rectangular teeth.

2. The combination with a conveyor and a motor, of speed-reducing driving connections between said motor and conveyor including a rotary wheel, an anchorednon-rotary notched stop wheel located concentric to and closely associated with said rotary wheel, said rotary wheel having at least one pivoted dog normally engageable with said notched stop wheel to prevent backward rotation of the transmission mechanism, but arranged to be thrown out of contact with said anchored wheel under rotation Ain the conveyor-driving direction, and means for locking said'dog out of engagement with the notches of Vsaid anchored wheel, the peripheral brake-acting flanges of said rotary wheel surrounding and enclosing said pivoted dog and the notched periphery of said anchored wheel.

ANDREW E. ROTHGARN. 

